In a vehicle diagnosis system disclosed, for example, in patent literature 1, a server and a communication terminal coordinate with each other to diagnose a vehicle. The vehicle diagnosis system is configured so that the server transmits instructions for a vehicle diagnosis worker (for example, a maintenance engineer) to the communication terminal, and that the communication terminal displays the transmitted instructions.
The inventors of the present disclosure have found the following regarding the vehicle diagnosis system. A configuration disclosed in patent literature 1 enables the communication terminal to display the instructions for the worker. Therefore, the worker can diagnose the vehicle according to the instructions. However, when the configuration disclosed in patent literature 1 is used, the instructions for the worker, which are displayed by the communication terminal, namely, the instructions provided from the server to the worker, are limited to instructions that the communication terminal receives from the server. Thus, the content of instructions (the amount of information) given from the server to the worker is limited. For example, complicated instructions describing multiple procedures might not be easily given to the worker. The complicated instructions are, for example, instructions for starting up an engine and then increasing the speed of the engine to a predetermined value. Further, when the content of instructions to be given from the server to the worker is to be increased, an increased burden might be placed on the communication terminal since, for example, it might be necessary to include a large-capacity storage portion into the communication terminal and perform a complicated maintenance procedure for software.